1. Field of the Invention
This invention relates to the art of prosthetic devices, methods and apparatus for implanting the devices between adjacent vertebrae to treat or prevent back pain in patients with ruptured or degenerated intervertebral discs. Specifically this invention deals with improvements in prosthetic strut forming plugs or blocks with roughened surfaces facilitating bone ingrowth from adjoining vertebrae.
2. Description of the Prior Art
As pointed out in my aforesaid Pat. No. 4,743,256 the leading cause of low back pain arises from rupture or degeneration of lumbar intervertebral discs. Pain in the lower extremeties of the back (sciatica) is caused by the compression of spinal nerve roots by damaged discs between the vertebra and low back pain is caused by collapse of the disc and the adverse effects of bearing the majority of the body weight through a damaged unstable vertebral joint. Surgical treatments for relief of the sciatic pain and lower back pain generally include the following: